I would stay away from thermaltake PSU's and go with corsair/xfx or seasonic, if you are using it mainly for gaming go with a 2500k and save yourself some money or get a bigger ssd. Other then that it looks like a nice build, but you might want to consider a 7950 instead of the 560ti's in sli unless you already have them.

Why switch when your rig is fine, nothing wrong with a PII rig, might as well wait for ivy bridge to come out because in most games and day to day applications you aren't going to notice a difference especially with those 2 GPU's.

8gb of memory is plenty as well, a few choices for gskill would be any model using the GBRL, GBXL, GBRM, GBSR identifiers. also I would go with the 1600 class ram, overall its performance benefit, and the small amount extra it costs is worth it.

If you do go 560 go for the 560 448 cores in SLI, or a single 7950/7970, much more performance, the 7950/7970 overclock like mad, and gain a ton of performance when you do.

Power supplies, Corsair/XFX/Seasonic/Enermax/NZXT, I would not be using Thermaltake. 750w+ is fine for any high quality pwoer supply for dual 7970/7950 or 560Ti/560 448 core. Seasonic X-760, XFX 750, HX750, Enermax Platimax, NZXT HALE, all wicked good power supplies with excellent build quality, and they can run thier rated wattage+ with no problems.

Core i5 2500k for gaming, no real need for a 2600k, if you were going that route, step up to a Sandy-E a few choices in there, the lowest of them being a quad with hyper just like the 2600k and its faster for not much more.

For the cooler, you could also go, H50/60/70 and put 2 fans on it for push/pull would be cheaper and outperform the H80, for the 2500k compared to 2600k you could step down a model or get a decent air cooler and you would be perfectly fine.

Also for motherboard, totaly up to you, but ASUS P8Z68-v or -V pro are way excellent motherboards, and they are full size ATX, much less likely to have spacing issues this way, and if I recall, they all have darn close to the same features, overclocking headroom etc, the -V is lower cost then the Gene as well.

For the memory cooler, you really do not need it unless you plan on chasing world overclocking attempts, DDR3 at 1.5v doesnt get anywhere close to hot enough, especially Gskill, its not needed as long as your computer is not in an oven, the standard Ripjaw or Sniper heatspreaders work perfectly fine, its more decoration then anything else.

Edit- MOST games show very little to no performance difference, between a 975 and a 2500k/2600k there are a few games, yes, but that does not make the Core i playable and the Phenom unplayable. BF3 as an example scales very well on AMD hardware. a 975 clocked to say 4.1-4.2 is plenty fast, especially with a good motherboard such as M5A99X EVO or Sabertooth 990FX. The only thing Intel does offer on some motherboards is slightly more performance from thier IO such as SATA performance and such.

Very few games show a massive difference, especially at higher resolutions, you are talking a difference of maybe 2 FPS or so with both at stock clocks, in single card use, and multi-card.

I'd say no to the memory cooler if your case has adequate air flow. In general, small fans make really annoying sounds.

Definitely get the 2600k. You'll appreciate the hyperthreading when doing your 3d animation. 16 gig of memory is fine too if you're doing 3d animation. It's just an extra 40 bucks if it's too much anyways.

For the powersupply I always recommend the ax series from corsair. An 850 watt will be more than you'll ever need. I always like having more power than I ever need as modern power supplies will not even turn on their fan if they have plenty of amps to spare. If you can't afford the ax850 then a 750 watt is just as good.

On the corsair h80 I would ask you to consider a tower cooler if you have the room. It's 110 bucks on the corsair website, just as much as a top of the line air cooler.

My main case is that the fan noise is rated at 22-39 dba, where a noctua NH-C14 is 10-19 dba. I cannot hear my three noctua case fans, all rated at 20 dba running at max voltage even with my case lid off.

The noctua nh-c14 also comes with premium thermal paste (skinii labs (sp) tested it as better than arctic silver, and almost as good as proilmek (sp)) and undervolt cords to quiet it down ever more, if u want.

Corsair does make a version of the h80 called the h70 where you supply your own fans.

Without looking so deep in other members posts,i think you might go with a 2700k,well some r going to argue that it's basically a higher priced 2600k,but fact say that it has more stock speed,and some OCers found it "a bit" easier to overclock with better temperatures,and basically 8 threads is fairly enough for ur 3D needs
I don't know if 3D animation softwares have actually a SLI profile to benefit from two cards,althought i would always reccommend going with single GPU in the system,especially if you're going not to use so many apps that doesn't benefit from SLI,so i would probably go for one GTX580,instead of two GTX560Ti,try some OC to squeeze some perfomance and probably add another card for physx like your GTX560 laying around,and upgrade to 580SLI once i have money!
for the mobo pick a Z68 board,but not any board,pick this one:the GIGABYTE Z68XP-UD3P because it supports both SLI and crossfireX and it has on the fly support for Ivy bridge and PCIE 3.0,so if you wanna upgrade with higher end CPUs,higher end GPUs no problem :)